Louis

This WordPress Plugin makes the default search also search based on meta data.
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WP Search Include Meta Data

License: GPLv2 or later WordPress plugin to include post meta data when using the default search

Dennis Bareis

WordPress revisions do not normally include custom fields or taxonomies. This plugin extends revisions to include taxonomies and custom fields from PODS etc, allowing previous states to be captured, compared & restored as expected.
Usage 
There is no user interface, once installed and activated it will start 
capturing custom field and taxonomy information. The rest is stock WordPress revision functionality, except that this plugin formats the extra data into an easy to read format for display in the comparison screens.
The look for the compare screens can be changed in “settings.ini” (including turn off or changing the CSS used).
Features
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Taxonomies are saved as metadata with a key such as “$TAXONOMY:light_conditions” for the “light_conditions” custom category. The values are a list of “ID=Name” pairs. These would generally sort to the top (or close to it).
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WordPress limits how the data is presented in the “Compare Revisions” screen, so the data is displayed as an alphabetically sorted list of fields and their values.
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You can filter out metadata keys with one or more regular expressions if you don’t care about their values. Filtered out metadata is not saved, displayed or restored.
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Some CSS is applied to the WordPress “Compare Revisions” screen which I believe makes it easier to understand, however you can disable this by renaming or deleting the CSS file (or adjusting “settings.ini”).
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The unicode characters also make the output easier to read and you can change their values or remove them via “settings.ini”. For example, you can tell the difference between a repeating field and a single field with many lines.
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Note that the “Restore This Revision” button restores what is on the right hand column and explains why it is greyed out for the last revision slot.
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Try it out 
<a href="https://tastewp.org/plugins/extend-revisions-for-custom-fields-and-taxonomies/" rel="nofollow ugc">Try it for free at TasteWP</a>
Reporting Issues 
Please turn on both “debug” and “info” in settings, perform the failing 
operation, and include the php log (part or all, if later specify the problem’s time as per the log)… 
Please provide screenshots if possible.

Extend Revisions for Custom Fields and Taxonomies

Possibly the only plugin that supports taxononomy revisions?

WordPress revisions do not normally include custom fields or taxonomies. This plugin extends revisions to include taxonomies and custom fields from PO …

WP Search Include Meta Data vs Extend Revisions for Custom Fields and Taxonomies